The Collaborative International Dictionary of English v.0.48:

Commonly \Com"mon*ly\, adv.
   1. Usually; generally; ordinarily; frequently; for the most
      part; as, confirmed habits commonly continue through life.
      [1913 Webster]

   2. In common; familiarly. [Obs.] --Spenser.
      [1913 Webster]

WordNet (r) 3.0 (2006):

commonly
    adv 1: under normal conditions; "usually she was late" [syn:
           normally, usually, unremarkably, commonly,
           ordinarily] [ant: outstandingly, remarkably,
           unco, unusually]

Moby Thesaurus II by Grady Ward, 1.0:

77 Moby Thesaurus words for "commonly":
   again and again, all in all, all things considered, altogether,
   as a rule, as a whole, as an approximation, as per usual,
   as things go, as usual, at large, banally, basely, broadly,
   broadly speaking, by and large, chiefly, commonplacely, communally,
   customarily, each to each, entre nous, familiarly, frequently,
   generally, generally speaking, habitually, hackneyedly, in general,
   in many instances, inferiorly, inter se, jointly, mainly,
   many a time, many times, matter-of-factly, meanly, most often,
   mostly, mutually, naturally, normally, normatively,
   not infrequently, not seldom, oft, often, often enough, oftentimes,
   ofttimes, on balance, on the whole, ordinarily, overall, plainly,
   poorly, predominantly, prescriptively, prevailingly, prosaically,
   regularly, repeatedly, respectively, roughly, roughly speaking,
   routinely, simply, speaking generally, stalely, to be expected,
   tritely, truistically, unoriginally, unseldom, usually,
   whenever you wish